This invention relates to an electric carrier with a motor controlled by a correlative position, particularly to one completely conforming humane driving capacity, with the speed of the electric carrier controlled by changing of the correlative position of the operator (such as a human person) and the thing controlled, and then the speed of the electric carrier may be altered in accordance with the speed of the operator. The electric carrier is moved by the motor, and there is a spring between the operator and the electric carrier, transmitting the force of the operator to the electric carrier. And the coefficient of the spring is chosen in such a way as the operator can control the electric carrier with a proper or no force. Then this electric carrier may have worthiness possible to be widely used in industries.
Generally speaking, conventional electric carriers with a motor controlled by the correlative positions nowadays have two ways of controlling its driving, an open route and a closed route.
The open route control, as shown in a block diagram of a flow chart in FIG. 1, has a controller for driving a motor, which directly moves an electric carrier. This kind of controlling way is simple and of low cost, but it can be applied to a narrow scope only. For example, if the electric carrier is a car running on land, the car can run very smoothly on a flat road, with the speed controlled by a controller coping with the car. But the car runs on an up or down slope, the motor cannot meet demand of the necessary speed, limited by the slope condition. Thus, the open route control mode is only suitable to an environment of little change or needing no particular condition.
As for the closed route control mode, referring to FIG. 2, has a difference that a speed meter is additionally provided in the open route control mode. The speed meter tests the speed of the motor and feeds the data to the controller controlling the motor so that the speed of the motor may be adjusted automatically to obtain stabilized speed of the motor. However, though the closed route control mode can guarantee to control the output of the motor, the object controlled is the motor, not the real thing to be controlled. Rigidity (such as the gap between gears) and load characteristic of the electric carrier may not be such as that calculated by theory, often produces large errors, so academies and scholars incessantly offer theory about motor control and its structure designs so as to acquire higher precision. But a new method may increase cost, not easily accepted by a non-consumer world.